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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2005, 2011
4 *
5 * Author(s): Rolf Adelsberger,
6 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
7 */
8
9#include <linux/device.h>
10#include <linux/mm.h>
11#include <linux/kexec.h>
12#include <linux/delay.h>
13#include <linux/reboot.h>
14#include <linux/ftrace.h>
15#include <linux/debug_locks.h>
16#include <asm/pfault.h>
17#include <asm/cio.h>
18#include <asm/setup.h>
19#include <asm/smp.h>
20#include <asm/ipl.h>
21#include <asm/diag.h>
22#include <asm/elf.h>
23#include <asm/asm-offsets.h>
24#include <asm/cacheflush.h>
25#include <asm/abs_lowcore.h>
26#include <asm/os_info.h>
27#include <asm/set_memory.h>
28#include <asm/stacktrace.h>
29#include <asm/switch_to.h>
30#include <asm/nmi.h>
31#include <asm/sclp.h>
32
33typedef void (*relocate_kernel_t)(unsigned long, unsigned long, unsigned long);
34typedef int (*purgatory_t)(int);
35
36extern const unsigned char relocate_kernel[];
37extern const unsigned long long relocate_kernel_len;
38
39#ifdef CONFIG_CRASH_DUMP
40
41/*
42 * Reset the system, copy boot CPU registers to absolute zero,
43 * and jump to the kdump image
44 */
45static void __do_machine_kdump(void *data)
46{
47 struct kimage *image = data;
48 purgatory_t purgatory;
49 unsigned long prefix;
50
51 purgatory = (purgatory_t)image->start;
52
53 /* store_status() saved the prefix register to lowcore */
54 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
55
56 /* Now do the reset */
57 s390_reset_system();
58
59 /*
60 * Copy dump CPU store status info to absolute zero.
61 * This need to be done *after* s390_reset_system set the
62 * prefix register of this CPU to zero
63 */
64 memcpy(absolute_pointer(__LC_FPREGS_SAVE_AREA),
65 phys_to_virt(prefix + __LC_FPREGS_SAVE_AREA), 512);
66
67 call_nodat(1, int, purgatory, int, 1);
68
69 /* Die if kdump returns */
70 disabled_wait();
71}
72
73/*
74 * Start kdump: create a LGR log entry, store status of all CPUs and
75 * branch to __do_machine_kdump.
76 */
77static noinline void __machine_kdump(void *image)
78{
79 struct mcesa *mcesa;
80 union ctlreg2 cr2_old, cr2_new;
81 int this_cpu, cpu;
82
83 lgr_info_log();
84 /* Get status of the other CPUs */
85 this_cpu = smp_find_processor_id(stap());
86 for_each_online_cpu(cpu) {
87 if (cpu == this_cpu)
88 continue;
89 if (smp_store_status(cpu))
90 continue;
91 }
92 /* Store status of the boot CPU */
93 mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
94 if (cpu_has_vx())
95 save_vx_regs((__vector128 *) mcesa->vector_save_area);
96 if (MACHINE_HAS_GS) {
97 local_ctl_store(2, &cr2_old.reg);
98 cr2_new = cr2_old;
99 cr2_new.gse = 1;
100 local_ctl_load(2, &cr2_new.reg);
101 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
102 local_ctl_load(2, &cr2_old.reg);
103 }
104 /*
105 * To create a good backchain for this CPU in the dump store_status
106 * is passed the address of a function. The address is saved into
107 * the PSW save area of the boot CPU and the function is invoked as
108 * a tail call of store_status. The backchain in the dump will look
109 * like this:
110 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
111 * The call to store_status() will not return.
112 */
113 store_status(__do_machine_kdump, image);
114}
115
116#endif /* CONFIG_CRASH_DUMP */
117
118/*
119 * Check if kdump checksums are valid: We call purgatory with parameter "0"
120 */
121static bool kdump_csum_valid(struct kimage *image)
122{
123#ifdef CONFIG_CRASH_DUMP
124 purgatory_t purgatory = (purgatory_t)image->start;
125 int rc;
126
127 rc = call_nodat(1, int, purgatory, int, 0);
128 return rc == 0;
129#else
130 return false;
131#endif
132}
133
134#ifdef CONFIG_CRASH_DUMP
135
136void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
137{
138 unsigned long addr, size;
139
140 for (addr = begin; addr < end; addr += PAGE_SIZE)
141 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
142 size = begin - crashk_res.start;
143 if (size)
144 os_info_crashkernel_add(crashk_res.start, size);
145 else
146 os_info_crashkernel_add(0, 0);
147}
148
149static void crash_protect_pages(int protect)
150{
151 unsigned long size;
152
153 if (!crashk_res.end)
154 return;
155 size = resource_size(&crashk_res);
156 if (protect)
157 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
158 else
159 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
160}
161
162void arch_kexec_protect_crashkres(void)
163{
164 crash_protect_pages(1);
165}
166
167void arch_kexec_unprotect_crashkres(void)
168{
169 crash_protect_pages(0);
170}
171
172#endif
173
174/*
175 * Give back memory to hypervisor before new kdump is loaded
176 */
177static int machine_kexec_prepare_kdump(void)
178{
179#ifdef CONFIG_CRASH_DUMP
180 if (MACHINE_IS_VM)
181 diag10_range(PFN_DOWN(crashk_res.start),
182 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
183 return 0;
184#else
185 return -EINVAL;
186#endif
187}
188
189int machine_kexec_prepare(struct kimage *image)
190{
191 void *reboot_code_buffer;
192
193 if (image->type == KEXEC_TYPE_CRASH)
194 return machine_kexec_prepare_kdump();
195
196 /* We don't support anything but the default image type for now. */
197 if (image->type != KEXEC_TYPE_DEFAULT)
198 return -EINVAL;
199
200 /* Get the destination where the assembler code should be copied to.*/
201 reboot_code_buffer = page_to_virt(image->control_code_page);
202
203 /* Then copy it */
204 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
205 return 0;
206}
207
208void machine_kexec_cleanup(struct kimage *image)
209{
210}
211
212void arch_crash_save_vmcoreinfo(void)
213{
214 struct lowcore *abs_lc;
215
216 VMCOREINFO_SYMBOL(lowcore_ptr);
217 VMCOREINFO_SYMBOL(high_memory);
218 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
219 vmcoreinfo_append_str("SAMODE31=%lx\n", (unsigned long)__samode31);
220 vmcoreinfo_append_str("EAMODE31=%lx\n", (unsigned long)__eamode31);
221 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
222 abs_lc = get_abs_lowcore();
223 abs_lc->vmcore_info = paddr_vmcoreinfo_note();
224 put_abs_lowcore(abs_lc);
225}
226
227void machine_shutdown(void)
228{
229}
230
231void machine_crash_shutdown(struct pt_regs *regs)
232{
233 set_os_info_reipl_block();
234}
235
236/*
237 * Do normal kexec
238 */
239static void __do_machine_kexec(void *data)
240{
241 unsigned long data_mover, entry, diag308_subcode;
242 struct kimage *image = data;
243
244 data_mover = page_to_phys(image->control_code_page);
245 entry = virt_to_phys(&image->head);
246 diag308_subcode = DIAG308_CLEAR_RESET;
247 if (sclp.has_iplcc)
248 diag308_subcode |= DIAG308_FLAG_EI;
249 s390_reset_system();
250
251 call_nodat(3, void, (relocate_kernel_t)data_mover,
252 unsigned long, entry,
253 unsigned long, image->start,
254 unsigned long, diag308_subcode);
255
256 /* Die if kexec returns */
257 disabled_wait();
258}
259
260/*
261 * Reset system and call either kdump or normal kexec
262 */
263static void __machine_kexec(void *data)
264{
265 pfault_fini();
266 tracing_off();
267 debug_locks_off();
268#ifdef CONFIG_CRASH_DUMP
269 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
270 __machine_kdump(data);
271#endif
272 __do_machine_kexec(data);
273}
274
275/*
276 * Do either kdump or normal kexec. In case of kdump we first ask
277 * purgatory, if kdump checksums are valid.
278 */
279void machine_kexec(struct kimage *image)
280{
281 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
282 return;
283 tracer_disable();
284 smp_send_stop();
285 smp_call_ipl_cpu(__machine_kexec, image);
286}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2005, 2011
4 *
5 * Author(s): Rolf Adelsberger,
6 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
7 */
8
9#include <linux/device.h>
10#include <linux/mm.h>
11#include <linux/kexec.h>
12#include <linux/delay.h>
13#include <linux/reboot.h>
14#include <linux/ftrace.h>
15#include <linux/debug_locks.h>
16#include <asm/cio.h>
17#include <asm/setup.h>
18#include <asm/smp.h>
19#include <asm/ipl.h>
20#include <asm/diag.h>
21#include <asm/elf.h>
22#include <asm/asm-offsets.h>
23#include <asm/cacheflush.h>
24#include <asm/abs_lowcore.h>
25#include <asm/os_info.h>
26#include <asm/set_memory.h>
27#include <asm/stacktrace.h>
28#include <asm/switch_to.h>
29#include <asm/nmi.h>
30#include <asm/sclp.h>
31
32typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long,
33 unsigned long);
34
35extern const unsigned char relocate_kernel[];
36extern const unsigned long long relocate_kernel_len;
37
38#ifdef CONFIG_CRASH_DUMP
39
40/*
41 * Reset the system, copy boot CPU registers to absolute zero,
42 * and jump to the kdump image
43 */
44static void __do_machine_kdump(void *image)
45{
46 int (*start_kdump)(int);
47 unsigned long prefix;
48
49 /* store_status() saved the prefix register to lowcore */
50 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
51
52 /* Now do the reset */
53 s390_reset_system();
54
55 /*
56 * Copy dump CPU store status info to absolute zero.
57 * This need to be done *after* s390_reset_system set the
58 * prefix register of this CPU to zero
59 */
60 memcpy(absolute_pointer(__LC_FPREGS_SAVE_AREA),
61 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
62
63 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
64 start_kdump = (void *)((struct kimage *) image)->start;
65 start_kdump(1);
66
67 /* Die if start_kdump returns */
68 disabled_wait();
69}
70
71/*
72 * Start kdump: create a LGR log entry, store status of all CPUs and
73 * branch to __do_machine_kdump.
74 */
75static noinline void __machine_kdump(void *image)
76{
77 struct mcesa *mcesa;
78 union ctlreg2 cr2_old, cr2_new;
79 int this_cpu, cpu;
80
81 lgr_info_log();
82 /* Get status of the other CPUs */
83 this_cpu = smp_find_processor_id(stap());
84 for_each_online_cpu(cpu) {
85 if (cpu == this_cpu)
86 continue;
87 if (smp_store_status(cpu))
88 continue;
89 }
90 /* Store status of the boot CPU */
91 mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
92 if (MACHINE_HAS_VX)
93 save_vx_regs((__vector128 *) mcesa->vector_save_area);
94 if (MACHINE_HAS_GS) {
95 __ctl_store(cr2_old.val, 2, 2);
96 cr2_new = cr2_old;
97 cr2_new.gse = 1;
98 __ctl_load(cr2_new.val, 2, 2);
99 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
100 __ctl_load(cr2_old.val, 2, 2);
101 }
102 /*
103 * To create a good backchain for this CPU in the dump store_status
104 * is passed the address of a function. The address is saved into
105 * the PSW save area of the boot CPU and the function is invoked as
106 * a tail call of store_status. The backchain in the dump will look
107 * like this:
108 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
109 * The call to store_status() will not return.
110 */
111 store_status(__do_machine_kdump, image);
112}
113
114static unsigned long do_start_kdump(unsigned long addr)
115{
116 struct kimage *image = (struct kimage *) addr;
117 int (*start_kdump)(int) = (void *)image->start;
118 int rc;
119
120 __arch_local_irq_stnsm(0xfb); /* disable DAT */
121 rc = start_kdump(0);
122 __arch_local_irq_stosm(0x04); /* enable DAT */
123 return rc;
124}
125
126#endif /* CONFIG_CRASH_DUMP */
127
128/*
129 * Check if kdump checksums are valid: We call purgatory with parameter "0"
130 */
131static bool kdump_csum_valid(struct kimage *image)
132{
133#ifdef CONFIG_CRASH_DUMP
134 int rc;
135
136 preempt_disable();
137 rc = call_on_stack(1, S390_lowcore.nodat_stack, unsigned long, do_start_kdump,
138 unsigned long, (unsigned long)image);
139 preempt_enable();
140 return rc == 0;
141#else
142 return false;
143#endif
144}
145
146#ifdef CONFIG_CRASH_DUMP
147
148void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
149{
150 unsigned long addr, size;
151
152 for (addr = begin; addr < end; addr += PAGE_SIZE)
153 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
154 size = begin - crashk_res.start;
155 if (size)
156 os_info_crashkernel_add(crashk_res.start, size);
157 else
158 os_info_crashkernel_add(0, 0);
159}
160
161static void crash_protect_pages(int protect)
162{
163 unsigned long size;
164
165 if (!crashk_res.end)
166 return;
167 size = resource_size(&crashk_res);
168 if (protect)
169 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
170 else
171 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
172}
173
174void arch_kexec_protect_crashkres(void)
175{
176 crash_protect_pages(1);
177}
178
179void arch_kexec_unprotect_crashkres(void)
180{
181 crash_protect_pages(0);
182}
183
184#endif
185
186/*
187 * Give back memory to hypervisor before new kdump is loaded
188 */
189static int machine_kexec_prepare_kdump(void)
190{
191#ifdef CONFIG_CRASH_DUMP
192 if (MACHINE_IS_VM)
193 diag10_range(PFN_DOWN(crashk_res.start),
194 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
195 return 0;
196#else
197 return -EINVAL;
198#endif
199}
200
201int machine_kexec_prepare(struct kimage *image)
202{
203 void *reboot_code_buffer;
204
205 if (image->type == KEXEC_TYPE_CRASH)
206 return machine_kexec_prepare_kdump();
207
208 /* We don't support anything but the default image type for now. */
209 if (image->type != KEXEC_TYPE_DEFAULT)
210 return -EINVAL;
211
212 /* Get the destination where the assembler code should be copied to.*/
213 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
214
215 /* Then copy it */
216 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
217 return 0;
218}
219
220void machine_kexec_cleanup(struct kimage *image)
221{
222}
223
224void arch_crash_save_vmcoreinfo(void)
225{
226 struct lowcore *abs_lc;
227 unsigned long flags;
228
229 VMCOREINFO_SYMBOL(lowcore_ptr);
230 VMCOREINFO_SYMBOL(high_memory);
231 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
232 vmcoreinfo_append_str("SAMODE31=%lx\n", __samode31);
233 vmcoreinfo_append_str("EAMODE31=%lx\n", __eamode31);
234 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
235 abs_lc = get_abs_lowcore(&flags);
236 abs_lc->vmcore_info = paddr_vmcoreinfo_note();
237 put_abs_lowcore(abs_lc, flags);
238}
239
240void machine_shutdown(void)
241{
242}
243
244void machine_crash_shutdown(struct pt_regs *regs)
245{
246 set_os_info_reipl_block();
247}
248
249/*
250 * Do normal kexec
251 */
252static void __do_machine_kexec(void *data)
253{
254 unsigned long diag308_subcode;
255 relocate_kernel_t data_mover;
256 struct kimage *image = data;
257
258 s390_reset_system();
259 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
260
261 __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
262 /* Call the moving routine */
263 diag308_subcode = DIAG308_CLEAR_RESET;
264 if (sclp.has_iplcc)
265 diag308_subcode |= DIAG308_FLAG_EI;
266 (*data_mover)(&image->head, image->start, diag308_subcode);
267
268 /* Die if kexec returns */
269 disabled_wait();
270}
271
272/*
273 * Reset system and call either kdump or normal kexec
274 */
275static void __machine_kexec(void *data)
276{
277 pfault_fini();
278 tracing_off();
279 debug_locks_off();
280#ifdef CONFIG_CRASH_DUMP
281 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
282 __machine_kdump(data);
283#endif
284 __do_machine_kexec(data);
285}
286
287/*
288 * Do either kdump or normal kexec. In case of kdump we first ask
289 * purgatory, if kdump checksums are valid.
290 */
291void machine_kexec(struct kimage *image)
292{
293 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
294 return;
295 tracer_disable();
296 smp_send_stop();
297 smp_call_ipl_cpu(__machine_kexec, image);
298}